Syringe plunger rod mount

ABSTRACT

A syringe device has a vial for medicaments having a first open end at a scaled second end. The first end having a plunger tip for sealing the end and has a finger grip means mounted adjacent the first. The needle and hub is slidably mounted on a needle on the second end in axial alignment with the sealed end to position said needle for access to the vial. The plunger rod has a first engagement on one end for engagement with the plunger tip and mounting means for detachably mounting the plunger between the finger grip and the hub to prevent access to the vial when the plunger is mounted thereon.

This is a continuation of application Ser. No. 08/145,578 filed Nov. 4,1993, now abandoned, which is a continuation of Ser. No. 07/759,221filed Sep. 26, 1991, now abandoned, which is a continuation of Ser. No.07/381,383, filed Jul. 18, 1989, now U.S. Pat. No. 5,067,947.

FIELD OF THE INVENTION

The present invention relates to hypodermic syringe assemblies and morespecifically to a prefilled disposable syringe assembly for medicamentsin injectable form.

BACKGROUND OF THE INVENTION

Disposable prefilled syringe assemblies for dispensing parenteralpharmaceuticals by injection are not new per se. Many syringe assemblieshave been proposed which employ a glass tube filled with the desiredmedicaments. At one end of the glass lube is a plunger tip whichfunctions as a seal prior to axial movement of tile plunger tip to emptythe contents of the syringe. At the other end of the glass tube or vialis a seal, often in the form of a elastomeric disk held in place by aplastic or metal cap. A plunger rod is generally associated with theplunger tip, and in many cases, the plunger tip and plunger rod are notfixedly attached to one another but are assembled at the time ofintended use of the syringe assembly. ()he such device is shown in U.S.Pat. No. 3,967,759.

The needle design which is often times used with disposable prefilledsyringe assemblies involves the rise of a double ended needle assemblywhich is attached to the sealed end of the glass vial in a firstposition where the needle is aligned with but not penetrating the seal.The needle assembly then is movable to a second position whereby theinteriorly pointing end of the needle penetrates the seal and providesaccess to the contents. The other end of the needle which is, of course,the end through which the medicine is administered to the patient, iscovered by a needle cover or needle shield. One such design is shown inU.S. Pat. No. 3,739,779.

These and other designs of similar structure are complicated and/oroversized. Other designs have certain functional disadvantages anddrawbacks, particularly when a single self-contained assembly is needed.

None of these patents disclose or suggest a device which is totallysuitable as a disposable prefilled syringe assembly. Particularly, noneof the prior art provides a compact assembly which is provided with afunctional locking mechanism to prevent inadvertent movement or damageto seals at either end of the prefilled container. It would be of greatadvantage if a syringe assembly could be provided which could beprefilled and stored or transported for a long period of time, followedby quick and efficient use when needed. Accordingly, it is an object ofthe present invention to provide such a device.

SUMMARY OF THE INVENTION

The above and other objects of the present invention may be achieved inthe following manner. Specifically, it has now been discovered that anew and useful syringe device may be provided having the followingelements.

The device includes a vial for medicaments and has a first open end anda sealed second end. On the first end, a plunger tip is positioned whichseals that end and which, when moved to the other end, will force thecontents of tile vial out of the device. A finger grip is mountedadjacent to that first end.

The second end of the vial is sealed, preferably using an elastomericliner mounted on the end with a fitted metal cap. A needle and hub meansfor slidably mounting a needle on the second end is provided and is inaxial alignment with the sealed end so as to position the needle foraccess to the vial. A plunger rod is provided having a first engagementmeans on one end for engaging the plunger tip. Preferably, tile otherend of the plunger rod includes an annular disk suitable foraccommodating the thumb as the plunger is depressed to evacuate thesyringe device.

Finally, a mounting device is provided for detachably mounting theplunger between the finger grip and the hub means. When the plunger ismounted in this position, the slidably mounted hub and needle cannotmove axially to engage the liner seal, thereby preventing access to tilecontents of the vial while the plunger rod is in the locking position.

In a preferred embodiment, tile hub means includes a double ended needleassembly which is axially movable from a first position during which theplunger is detachably mounted to the device and a second position whichprovides access by the needle to the vial. This is best accomplished inthis embodiment providing said hub means with an inwardly facing annularring and providing the second end of the vial with a pair of annulargrooves defining the first and second positions respectively when theannular ring engages those grooves. Those grooves may conveniently beformed by the metal cap or other device used to mount the elastomericliner which seals the end of the vial.

The device further includes a needle cover or shield which mayconveniently be attached to the hub means using an annular ring andgroove assembly for snap filling. The plunger rod may be hollow andaxially overlie the needle shield and a portion of tile needle end oftile syringe in one particularly preferred embodiment, tile plunger rodincludes an annular disk which is sized to engage a similar annularopening in tile finger grip. The finger grip, of course, has a firstannular opening which is sized to permit said plunger rod and saidplunger tip to be engaged for use in dispensing the contents of thesyringe device. The second annular opening is larger and is sized toreceive tile annular disk on tile plunger when tile plunger rod is fullyinserted into the vial to completely expel tile contents of the syringe.Additionally, a holding means for maintaining tile annular disk of tileplunger in the second annular opening of the grip means is provided,such as by a snap fill assembly, so that it is at least very difficultto remove the plunger rod once it has expelled the contents of thesyringe device. This safety feature is part of the benefits obtained bythe use of disposable systems. At least when tile snap fit used syringeis picked up in a casual or accidental encounter, it prevents reusingthee syringe device in accordance with its design, which is primarilyintended for prefilling and disposal after a single use.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects of tile present invention and the variousfeatures and details of the operation and construction thereof arehereinafter more fully set forth with reference to the accompanyingdrawings, where:

FIG. 1 is a plan view of a prefilled syringe and its associated plungerrod mounting in accordance with this invention;

FIG. 2 is a left hand end view taken on the line 2,2 of FIG. 1 showingcertain details of the finger grip portion of the refillable syringe;

FIG. 3 is a right hand end view taken on the line 3,3 of FIG. 1 showingcertain details of the hollow plunger rod axially aligned and overlyingthe needle shield and needle end of the syringe shown in FIG. 1;

FIG. 4 is an enlarged sectional side elevational view with portions ofcontinuous detail removed taken on the line 4,4 of FIG. 1 illustratingdetails of the syringe and plunger rod shown in FIG. 1;

FIG. 5 is an enlarged transverse sectional view taken on the line 5,5 ofFIG. 4 illustrating certain details of the sliding double ended needlehub assembly;

FIG. 6 is an enlarged fragmentary sectional view taken on tile line 6,6of FIG. 4 with the plunger rod shown in clot and dash outline. Theplunger rod having been removed prior to attachment to the piston;

FIG. 7 is an enlarged sectional plan view similar to FIG. 4 but showingthe plunger rod threadably engaged with the piston prior to use;

FIG. 8 is a fragmentary sectional view similar to FIG. 6 but showing theneedle shield in dot and dash outlining having been removed. Theslidable double ended needle hub assembly having been activated to armthe syringe;

FIG. 9 is an enlarged fragmentary sectional view of a portion of tilefinger grip end of the syringe illustrating the interlocking of theplunger rod terminal end within the finger grip member upon completionof stroke;

FIG. 10 is a modification of tile prefillable syringe shown in FIG. 1illustrating the plunger rod mounted in a parallel axially alignedrelationship to tile prefilled syringe assembly, tile plunger rodcaptured between a socket in the finger grip member and a slot on theslidable double ended needle assembly to prevent premature arming of thesyringe to shorten the length of the prefilled syringe package;

FIGS. 11 and 12 are sectional views taken on the lines 11,11 and 12,12of FIG. 10 showing additional details of the socket and slot retainingmeans.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings and particularly to FIGS. 1 through 12thereof, there is illustrated one embodiment of a disposable prefilledsyringe device in accordance with tile invention which is generallydesignated by tile reference numeral 10. The syringe device 10 isadapted to be prefilled with any suitable medicament which doctors,veterinarians,and other users of syringes might wish to have readilyavailable and storedover a long period of time. Further, devices filledwith pharmaceutical materials in a ideally clean environment such as ina pharmaceutical laboratory cannot be duplicated in tile field whereprefilled syringes areoften times needed. Thus refilling the device inthe field presents additional risk to the patients and, accordingly,tile units are normally disposable.

The syringe device 10 of tile present invention includes a glass vial orcartridge 11 which has a finger grip 13 mounted on one end and a hub 15for mounting a needle 17 on the other end. Typically, the needle 17 willhave a needle shield 19. In an alternative embodiment, the hub 15 mightinclude a Luer cap and Luer lock.

Also provided as part of the device generally is a hollow plunger rod 21which is fitted with a threaded end 23. As will be describedhereinafter, the end of the vial 11 having the hub 15 is sealed prior touse. The contents 25 are kept in the vial 11 by a plunger lip 27 whicheffectively seals tile other end of tile vial 11. The plunger tip willusually be madefrom a particular formulation which the pharmaceuticalmanufacturer knows is compatible with the medicament 25. A preferredmaterial is manufacturedfrom an extremely stable elastomeric materialand is designated 4416/50 grey, manufactured by The West Company. Theplunger tip 27 is also fitted with threads 29 for engagement with thethreads 23 of the plunger rod 21.

The finger grip 13 is slidably mounted onto the tube 11 by a base 31which may also include ring 32 to prevent movement of the finger grip 13too fardown the tube 11. At the other end of the tube 11, shown insection in FIG.4, is a larger skirt 33 which forms a part of the needlehub means 15 whichmounts the needle 17. The hub 15 has a tube engagingportion 35 which is sized to engage the metal tin 37 which secures arubber liner to seal tileend of tile tube, as will be describedhereinafter. The metal cap 37 has anannular groove 39 of slightlysmaller diameter than tile diameter of the cap 37. The skirt 33 also hasa plurality of projections 41 which support the skirt 33 on tile outsidediameter of the glass vial 11.

As shown in FIGS. 6 and 8, the needle assembly includes a double endedneedle 17 which is held in place by a needle mount 45 and a sealingelement 47. The needle shield or cover 19 is maintained in place on theneedle mount 45 by an annular groove 49 and an annular ridge 51. In FIG.6, the annular groove 49 is in tile needle shield 19 and tile annularridge 51 is located on the needle cover 45. The groove 49 and ridge 51allow for a snap fit of tile needle cover 19 to protect the needle priorto use.

Needle holder 15 also includes an internal annular ridge 53 which ispositioned to cooperatively fit in annular groove 39 when the needle 17isin a first position in axial alignment with the vial 11 but notpenetratingtile rubber seal 57 which is held by the metal cap 37 on tileend of the glass vial 11. The glass vial end terminates in a neckportion 43 which defines a second groove 55 as is shown in FIGS. 6 and8. When tile needle 17 is in tile storage position, as shown in FIG. 6,the annular ridge 53 is firmly positioned in groove 39. When the devicebecomes operational, the needle 17 is moved in the direction of arrow 59and penetrates the elastomeric seal 57 which is held by the metal cap37. The annular ridge 53 then becomes positioned in the region or groove55 on the neck 43 of the vial 11, thereby locating the needle hub in anactive position.

Before the needle 17 has penetrated the elastomeric seal 57 to provideaccess to the contents 25 of the vial 11, the hollow plunger rod 21 isattached to the plunger tip 27 by threading the end 29 into threads 23andproviding for a positive engagement of the plunger tip 27 and plungerrod 21. The syringe is then ready to operate after tile needle shield 19is removed. The groove 49 and ridge 51 separate easily and the needleshield 19 can be saved to reshield the needle after use.

In one embodiment, the plunger rod 21 contains a hollow portion, such asshown in FIG. 7, which ,is sized so that the hub 15 with the needle 17canbe inserted in the hollow portion without the shield 19. The hub 15with the needle 17 can be inserted into the hollow portion without theshield 19. The hub 15 as seen in FIG. 6, has an annular ring 52 whichfits insideridge 54 of plunger rod 21, and this snap fit preventsremoval of tile hub and keeps the needle from being reused. Ring 52 andridge 54 are an additional safety feature.

The plunger tip 27 will expel all of the contents 25 from the vial 11when the plunger rod 21 is inserted all the way into the vial 11, asshown in FIG. 9 by arrow 61. Plunger rod 21 includes a radiallyextending annular disk 63 which allows the thumb to exert steadypressure on the plunger rod21. When the plunger rod is fully extendedinto the glass vial 11, as shownin FIG. 9, the annular disk 63 fitsinside the finger grip 13 and snap fitspast the annular ridge 65,thereby locking tile plunger rod 21 inside the vial 11. Thus, since tilesyringe device is intended to be disposable after one use, tile plungerrod cannot be withdrawn without great difficulty. This safety factorreduces the likelihood of the syringe device being reused eveninadvertently by those who temporarily forget that the device is to bedisposed of after a single use.

In a preferred embodiment, shown in FIG. 10, tile plunger rod 21 ismountedby a mounting means on the syringe itself. This mounting meansincludes a groove or lip 67 which is aligned to mate with the annulardisk 63 of plunger rod 21. Similarly, the slot 69 is located on thefinger grip 13 toaccommodate the threaded end 23 of plunger rod 21. Whenthe plunger rod 21 is in place as shown in FIG. 10, tile hub 15 is inits first position, shown in FIG. 6, where the two way needle 17 has notyet penetrated the elastomeric seal 57. If desired, the groove 67 or theslot 69 can be tack welded to the plunger rod 29 by the application oflocalized heat. In thismanner, tire plunger rod is locked onto thesyringe itself and the two way needle cannot penetrate the elastomericmembrane of the syringe device.

After the completely assembled unit has left tile factory in thiscondition, it is tamper-evident as well as secure. As long as theplunger rod 21 remains fixedly attached to the finger grip 13 and theskirt 33 of hub 15, the contents 25 are secure. When it is time to usethe disposable prefilled syringe, the plunger rod 21 is removed from themounting means by pulling annular disk 63 out of groove 67 and removingthe threaded end 23 from the slot 69. The threaded end 23 is thenthreaded onto threads 29 of plunger tip 23. The hub assembly 15 isdepressed so that ridge 53 is removed from annular groove 39 and entersinto the neck area 55 of the vial 11. During this time, tire interiorend of needle 17 punctures the elastomeric seal 57, permitting access tothe contents. The device is thenready for use to inject the desiredmedicament into the patient or IV system such as a heparin lock. Bypressing the plunger rod 21 all the way into tile glass vial 11, theannular disk 63 snaps past annular ridge 65, thereby preventing reuse ofthe syringe. The device is now ready for proper disposal.

The device of this invention is compact and has a much shorter packagesize. This permits the use of the device in hospital carts and the likewhich have limited drawer length. When the device is used, insertion ofplunger rod 21 into vial 11, and insertion of hub 15 and needle 17 intoplunger rod 21, as shown in FIG. 9, permits safe disposal thereof.

While particular embodiments of tile present invention have beenillustrated and described herein, it is not intended to limit theinvention and changes and modifications may be made therein within thescope of the following claims.

What is claimed is:
 1. A syringe device, comprising:a vial formedicaments having a first open end and a penetratable seal at itsopposite second end, said first end having a plunger tip; finger gripmeans mounted adjacent said first end; an elongated hollow plunger rodmovable axially in the vial to a final discharge position whenmedicament is discharged, said hollow plunger rod having a firstengagement means on one end for engagement with said plunger tip, saidhollow plunger rod having first locking means located adjacent its openend for inserting a spent needle interiorly of the hollow plunger rod;needle hub means for mounting a needle on said second end in axialalignment with said seal actuatable axially between an unarmed positionspaced from said seal and an armed position penetrating said seal toaccess contents of said vial; and means defining a cavity and an annularrib in said finger grip means and said hollow plunger rod having aradially outwardly directed disk portion which is sized to snap fit intosaid cavity behind said rib when said hollow plunger rod is actuated tosaid final discharge position such that the end of said hollow plungerrod is flush with said finger means grip.
 2. A syringe device,comprising:a vial for medicaments having a first open end and apenetratable seal at its opposite second end, said first end having aplunger tip; finger grip means mounted adjacent said first end; needlehub for mounting a needle on said second end in axial alignment withsaid seal actuatable axially between an unarmed position spaced fromsaid seal and an armed position penetrating said seal to access contentsof said vial; an elongated hollow plunger rod movable axially in thevial to a final discharge position when medicament is discharged, saidhollow plunger rod having a first engagement means on one end forengagement with said plunger tip, said hollow plunger rod having firstlocking means located adjacent its open end and said needle hub meanshaving complementary second locking means whereby a spent needle can beinserted interiorly of the hollow plunger rod and the locking meansinterengaged to safely hold the spent needle in place in the hollowplunger rod; and means defining a cavity and an annular rib in saidfinger grip means and said hollow plunger rod having a radiallyoutwardly directed disk portion which is sized to snap fit into saidcavity behind said rib when said hollow plunger rod is actuated to saidfinal discharge position such that the end of said hollow plunger rod isflush with said finger grip means.
 3. A syringe device, comprising:avial for medicaments having a first open end and a penetratable seal atits opposite second end, said first end having a plunger tip; fingergrip means mounted adjacent said first end; needle hub for mounting aneedle on said second end in axial alignment with said seal actuatableaxially between an unarmed position spaced from said seal and an armedposition penetrating said seal to access contents of said vial; anelongated hollow plunger rod movable axially in the vial to a finaldischarge position when medicament is discharged, said hollow plungerrod having a first engagement means on one end for engagement with saidplunger tip, said hollow plunger rod having first locking means locatedadjacent its open end and said needle hub means having complementarysecond locking means whereby a spent needle can be inserted interiorlyof the hollow plunger rod and the locking means interengaged to safelyhold the spent needle in place in the hollow plunger rod; and meansdefining a cavity and an annular rib in said finger grip means and saidhollow plunger rod having a radially outwardly directed disk portionwhich is sized to snap fit into said cavity behind said rib when saidhollow plunger rod is actuated to said final discharge position suchthat the end of said hollow plunger rod is flush with said finger gripmeans.